// Copyright (c) 1994-2006 Sun Microsystems Inc. // All Rights Reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // - Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // - Redistribution in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // // - Neither the name of Sun Microsystems or the names of contributors may // be used to endorse or promote products derived from this software without // specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS // IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, // THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // The original source code covered by the above license above has been // modified significantly by Google Inc. // Copyright 2006-2009 the V8 project authors. All rights reserved. #include "v8.h" #include "arguments.h" #include "execution.h" #include "ic-inl.h" #include "factory.h" #include "runtime.h" #include "serialize.h" #include "stub-cache.h" #include "regexp-stack.h" namespace v8 { namespace internal { // ----------------------------------------------------------------------------- // Implementation of Label int Label::pos() const { if (pos_ < 0) return -pos_ - 1; if (pos_ > 0) return pos_ - 1; UNREACHABLE(); return 0; } // ----------------------------------------------------------------------------- // Implementation of RelocInfoWriter and RelocIterator // // Encoding // // The most common modes are given single-byte encodings. Also, it is // easy to identify the type of reloc info and skip unwanted modes in // an iteration. // // The encoding relies on the fact that there are less than 14 // different relocation modes. // // embedded_object: [6 bits pc delta] 00 // // code_taget: [6 bits pc delta] 01 // // position: [6 bits pc delta] 10, // [7 bits signed data delta] 0 // // statement_position: [6 bits pc delta] 10, // [7 bits signed data delta] 1 // // any nondata mode: 00 [4 bits rmode] 11, // rmode: 0..13 only // 00 [6 bits pc delta] // // pc-jump: 00 1111 11, // 00 [6 bits pc delta] // // pc-jump: 01 1111 11, // (variable length) 7 - 26 bit pc delta, written in chunks of 7 // bits, the lowest 7 bits written first. // // data-jump + pos: 00 1110 11, // signed intptr_t, lowest byte written first // // data-jump + st.pos: 01 1110 11, // signed intptr_t, lowest byte written first // // data-jump + comm.: 10 1110 11, // signed intptr_t, lowest byte written first // const int kMaxRelocModes = 14; const int kTagBits = 2; const int kTagMask = (1 << kTagBits) - 1; const int kExtraTagBits = 4; const int kPositionTypeTagBits = 1; const int kSmallDataBits = kBitsPerByte - kPositionTypeTagBits; const int kEmbeddedObjectTag = 0; const int kCodeTargetTag = 1; const int kPositionTag = 2; const int kDefaultTag = 3; const int kPCJumpTag = (1 << kExtraTagBits) - 1; const int kSmallPCDeltaBits = kBitsPerByte - kTagBits; const int kSmallPCDeltaMask = (1 << kSmallPCDeltaBits) - 1; const int kVariableLengthPCJumpTopTag = 1; const int kChunkBits = 7; const int kChunkMask = (1 << kChunkBits) - 1; const int kLastChunkTagBits = 1; const int kLastChunkTagMask = 1; const int kLastChunkTag = 1; const int kDataJumpTag = kPCJumpTag - 1; const int kNonstatementPositionTag = 0; const int kStatementPositionTag = 1; const int kCommentTag = 2; uint32_t RelocInfoWriter::WriteVariableLengthPCJump(uint32_t pc_delta) { // Return if the pc_delta can fit in kSmallPCDeltaBits bits. // Otherwise write a variable length PC jump for the bits that do // not fit in the kSmallPCDeltaBits bits. if (is_uintn(pc_delta, kSmallPCDeltaBits)) return pc_delta; WriteExtraTag(kPCJumpTag, kVariableLengthPCJumpTopTag); uint32_t pc_jump = pc_delta >> kSmallPCDeltaBits; ASSERT(pc_jump > 0); // Write kChunkBits size chunks of the pc_jump. for (; pc_jump > 0; pc_jump = pc_jump >> kChunkBits) { byte b = pc_jump & kChunkMask; *--pos_ = b << kLastChunkTagBits; } // Tag the last chunk so it can be identified. *pos_ = *pos_ | kLastChunkTag; // Return the remaining kSmallPCDeltaBits of the pc_delta. return pc_delta & kSmallPCDeltaMask; } void RelocInfoWriter::WriteTaggedPC(uint32_t pc_delta, int tag) { // Write a byte of tagged pc-delta, possibly preceded by var. length pc-jump. pc_delta = WriteVariableLengthPCJump(pc_delta); *--pos_ = pc_delta << kTagBits | tag; } void RelocInfoWriter::WriteTaggedData(intptr_t data_delta, int tag) { *--pos_ = data_delta << kPositionTypeTagBits | tag; } void RelocInfoWriter::WriteExtraTag(int extra_tag, int top_tag) { *--pos_ = top_tag << (kTagBits + kExtraTagBits) | extra_tag << kTagBits | kDefaultTag; } void RelocInfoWriter::WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag) { // Write two-byte tagged pc-delta, possibly preceded by var. length pc-jump. pc_delta = WriteVariableLengthPCJump(pc_delta); WriteExtraTag(extra_tag, 0); *--pos_ = pc_delta; } void RelocInfoWriter::WriteExtraTaggedData(intptr_t data_delta, int top_tag) { WriteExtraTag(kDataJumpTag, top_tag); for (int i = 0; i < kIntptrSize; i++) { *--pos_ = data_delta; // Signed right shift is arithmetic shift. Tested in test-utils.cc. data_delta = data_delta >> kBitsPerByte; } } void RelocInfoWriter::Write(const RelocInfo* rinfo) { #ifdef DEBUG byte* begin_pos = pos_; #endif Counters::reloc_info_count.Increment(); ASSERT(rinfo->pc() - last_pc_ >= 0); ASSERT(RelocInfo::NUMBER_OF_MODES < kMaxRelocModes); // Use unsigned delta-encoding for pc. uint32_t pc_delta = rinfo->pc() - last_pc_; RelocInfo::Mode rmode = rinfo->rmode(); // The two most common modes are given small tags, and usually fit in a byte. if (rmode == RelocInfo::EMBEDDED_OBJECT) { WriteTaggedPC(pc_delta, kEmbeddedObjectTag); } else if (rmode == RelocInfo::CODE_TARGET) { WriteTaggedPC(pc_delta, kCodeTargetTag); } else if (RelocInfo::IsPosition(rmode)) { // Use signed delta-encoding for data. intptr_t data_delta = rinfo->data() - last_data_; int pos_type_tag = rmode == RelocInfo::POSITION ? kNonstatementPositionTag : kStatementPositionTag; // Check if data is small enough to fit in a tagged byte. // We cannot use is_intn because data_delta is not an int32_t. if (data_delta >= -(1 << (kSmallDataBits-1)) && data_delta < 1 << (kSmallDataBits-1)) { WriteTaggedPC(pc_delta, kPositionTag); WriteTaggedData(data_delta, pos_type_tag); last_data_ = rinfo->data(); } else { // Otherwise, use costly encoding. WriteExtraTaggedPC(pc_delta, kPCJumpTag); WriteExtraTaggedData(data_delta, pos_type_tag); last_data_ = rinfo->data(); } } else if (RelocInfo::IsComment(rmode)) { // Comments are normally not generated, so we use the costly encoding. WriteExtraTaggedPC(pc_delta, kPCJumpTag); WriteExtraTaggedData(rinfo->data() - last_data_, kCommentTag); last_data_ = rinfo->data(); } else { // For all other modes we simply use the mode as the extra tag. // None of these modes need a data component. ASSERT(rmode < kPCJumpTag && rmode < kDataJumpTag); WriteExtraTaggedPC(pc_delta, rmode); } last_pc_ = rinfo->pc(); #ifdef DEBUG ASSERT(begin_pos - pos_ <= kMaxSize); #endif } inline int RelocIterator::AdvanceGetTag() { return *--pos_ & kTagMask; } inline int RelocIterator::GetExtraTag() { return (*pos_ >> kTagBits) & ((1 << kExtraTagBits) - 1); } inline int RelocIterator::GetTopTag() { return *pos_ >> (kTagBits + kExtraTagBits); } inline void RelocIterator::ReadTaggedPC() { rinfo_.pc_ += *pos_ >> kTagBits; } inline void RelocIterator::AdvanceReadPC() { rinfo_.pc_ += *--pos_; } void RelocIterator::AdvanceReadData() { intptr_t x = 0; for (int i = 0; i < kIntptrSize; i++) { x |= static_cast<intptr_t>(*--pos_) << i * kBitsPerByte; } rinfo_.data_ += x; } void RelocIterator::AdvanceReadVariableLengthPCJump() { // Read the 32-kSmallPCDeltaBits most significant bits of the // pc jump in kChunkBits bit chunks and shift them into place. // Stop when the last chunk is encountered. uint32_t pc_jump = 0; for (int i = 0; i < kIntSize; i++) { byte pc_jump_part = *--pos_; pc_jump |= (pc_jump_part >> kLastChunkTagBits) << i * kChunkBits; if ((pc_jump_part & kLastChunkTagMask) == 1) break; } // The least significant kSmallPCDeltaBits bits will be added // later. rinfo_.pc_ += pc_jump << kSmallPCDeltaBits; } inline int RelocIterator::GetPositionTypeTag() { return *pos_ & ((1 << kPositionTypeTagBits) - 1); } inline void RelocIterator::ReadTaggedData() { int8_t signed_b = *pos_; // Signed right shift is arithmetic shift. Tested in test-utils.cc. rinfo_.data_ += signed_b >> kPositionTypeTagBits; } inline RelocInfo::Mode RelocIterator::DebugInfoModeFromTag(int tag) { if (tag == kStatementPositionTag) { return RelocInfo::STATEMENT_POSITION; } else if (tag == kNonstatementPositionTag) { return RelocInfo::POSITION; } else { ASSERT(tag == kCommentTag); return RelocInfo::COMMENT; } } void RelocIterator::next() { ASSERT(!done()); // Basically, do the opposite of RelocInfoWriter::Write. // Reading of data is as far as possible avoided for unwanted modes, // but we must always update the pc. // // We exit this loop by returning when we find a mode we want. while (pos_ > end_) { int tag = AdvanceGetTag(); if (tag == kEmbeddedObjectTag) { ReadTaggedPC(); if (SetMode(RelocInfo::EMBEDDED_OBJECT)) return; } else if (tag == kCodeTargetTag) { ReadTaggedPC(); if (*(reinterpret_cast<int*>(rinfo_.pc())) == 0x61) { tag = 0; } if (SetMode(RelocInfo::CODE_TARGET)) return; } else if (tag == kPositionTag) { ReadTaggedPC(); Advance(); // Check if we want source positions. if (mode_mask_ & RelocInfo::kPositionMask) { // Check if we want this type of source position. if (SetMode(DebugInfoModeFromTag(GetPositionTypeTag()))) { // Finally read the data before returning. ReadTaggedData(); return; } } } else { ASSERT(tag == kDefaultTag); int extra_tag = GetExtraTag(); if (extra_tag == kPCJumpTag) { int top_tag = GetTopTag(); if (top_tag == kVariableLengthPCJumpTopTag) { AdvanceReadVariableLengthPCJump(); } else { AdvanceReadPC(); } } else if (extra_tag == kDataJumpTag) { // Check if we want debug modes (the only ones with data). if (mode_mask_ & RelocInfo::kDebugMask) { int top_tag = GetTopTag(); AdvanceReadData(); if (SetMode(DebugInfoModeFromTag(top_tag))) return; } else { // Otherwise, just skip over the data. Advance(kIntptrSize); } } else { AdvanceReadPC(); if (SetMode(static_cast<RelocInfo::Mode>(extra_tag))) return; } } } done_ = true; } RelocIterator::RelocIterator(Code* code, int mode_mask) { rinfo_.pc_ = code->instruction_start(); rinfo_.data_ = 0; // relocation info is read backwards pos_ = code->relocation_start() + code->relocation_size(); end_ = code->relocation_start(); done_ = false; mode_mask_ = mode_mask; if (mode_mask_ == 0) pos_ = end_; next(); } RelocIterator::RelocIterator(const CodeDesc& desc, int mode_mask) { rinfo_.pc_ = desc.buffer; rinfo_.data_ = 0; // relocation info is read backwards pos_ = desc.buffer + desc.buffer_size; end_ = pos_ - desc.reloc_size; done_ = false; mode_mask_ = mode_mask; if (mode_mask_ == 0) pos_ = end_; next(); } // ----------------------------------------------------------------------------- // Implementation of RelocInfo #ifdef ENABLE_DISASSEMBLER const char* RelocInfo::RelocModeName(RelocInfo::Mode rmode) { switch (rmode) { case RelocInfo::NONE: return "no reloc"; case RelocInfo::EMBEDDED_OBJECT: return "embedded object"; case RelocInfo::EMBEDDED_STRING: return "embedded string"; case RelocInfo::CONSTRUCT_CALL: return "code target (js construct call)"; case RelocInfo::CODE_TARGET_CONTEXT: return "code target (context)"; case RelocInfo::CODE_TARGET: return "code target"; case RelocInfo::RUNTIME_ENTRY: return "runtime entry"; case RelocInfo::JS_RETURN: return "js return"; case RelocInfo::COMMENT: return "comment"; case RelocInfo::POSITION: return "position"; case RelocInfo::STATEMENT_POSITION: return "statement position"; case RelocInfo::EXTERNAL_REFERENCE: return "external reference"; case RelocInfo::INTERNAL_REFERENCE: return "internal reference"; case RelocInfo::NUMBER_OF_MODES: UNREACHABLE(); return "number_of_modes"; } return "unknown relocation type"; } void RelocInfo::Print() { PrintF("%p %s", pc_, RelocModeName(rmode_)); if (IsComment(rmode_)) { PrintF(" (%s)", data_); } else if (rmode_ == EMBEDDED_OBJECT) { PrintF(" ("); target_object()->ShortPrint(); PrintF(")"); } else if (rmode_ == EXTERNAL_REFERENCE) { ExternalReferenceEncoder ref_encoder; PrintF(" (%s) (%p)", ref_encoder.NameOfAddress(*target_reference_address()), *target_reference_address()); } else if (IsCodeTarget(rmode_)) { Code* code = Code::GetCodeFromTargetAddress(target_address()); PrintF(" (%s) (%p)", Code::Kind2String(code->kind()), target_address()); } else if (IsPosition(rmode_)) { PrintF(" (%d)", data()); } PrintF("\n"); } #endif // ENABLE_DISASSEMBLER #ifdef DEBUG void RelocInfo::Verify() { switch (rmode_) { case EMBEDDED_OBJECT: Object::VerifyPointer(target_object()); break; case CONSTRUCT_CALL: case CODE_TARGET_CONTEXT: case CODE_TARGET: { // convert inline target address to code object Address addr = target_address(); ASSERT(addr != NULL); // Check that we can find the right code object. HeapObject* code = HeapObject::FromAddress(addr - Code::kHeaderSize); Object* found = Heap::FindCodeObject(addr); ASSERT(found->IsCode()); ASSERT(code->address() == HeapObject::cast(found)->address()); break; } case RelocInfo::EMBEDDED_STRING: case RUNTIME_ENTRY: case JS_RETURN: case COMMENT: case POSITION: case STATEMENT_POSITION: case EXTERNAL_REFERENCE: case INTERNAL_REFERENCE: case NONE: break; case NUMBER_OF_MODES: UNREACHABLE(); break; } } #endif // DEBUG // ----------------------------------------------------------------------------- // Implementation of ExternalReference ExternalReference::ExternalReference(Builtins::CFunctionId id) : address_(Redirect(Builtins::c_function_address(id))) {} ExternalReference::ExternalReference(Builtins::Name name) : address_(Builtins::builtin_address(name)) {} ExternalReference::ExternalReference(Runtime::FunctionId id) : address_(Redirect(Runtime::FunctionForId(id)->entry)) {} ExternalReference::ExternalReference(Runtime::Function* f) : address_(Redirect(f->entry)) {} ExternalReference::ExternalReference(const IC_Utility& ic_utility) : address_(Redirect(ic_utility.address())) {} #ifdef ENABLE_DEBUGGER_SUPPORT ExternalReference::ExternalReference(const Debug_Address& debug_address) : address_(debug_address.address()) {} #endif ExternalReference::ExternalReference(StatsCounter* counter) : address_(reinterpret_cast<Address>(counter->GetInternalPointer())) {} ExternalReference::ExternalReference(Top::AddressId id) : address_(Top::get_address_from_id(id)) {} ExternalReference::ExternalReference(const SCTableReference& table_ref) : address_(table_ref.address()) {} ExternalReference ExternalReference::perform_gc_function() { return ExternalReference(Redirect(FUNCTION_ADDR(Runtime::PerformGC))); } ExternalReference ExternalReference::builtin_passed_function() { return ExternalReference(&Builtins::builtin_passed_function); } ExternalReference ExternalReference::random_positive_smi_function() { return ExternalReference(Redirect(FUNCTION_ADDR(V8::RandomPositiveSmi))); } ExternalReference ExternalReference::the_hole_value_location() { return ExternalReference(Factory::the_hole_value().location()); } ExternalReference ExternalReference::address_of_stack_guard_limit() { return ExternalReference(StackGuard::address_of_jslimit()); } ExternalReference ExternalReference::address_of_regexp_stack_limit() { return ExternalReference(RegExpStack::limit_address()); } ExternalReference ExternalReference::new_space_start() { return ExternalReference(Heap::NewSpaceStart()); } ExternalReference ExternalReference::new_space_allocation_top_address() { return ExternalReference(Heap::NewSpaceAllocationTopAddress()); } ExternalReference ExternalReference::heap_always_allocate_scope_depth() { return ExternalReference(Heap::always_allocate_scope_depth_address()); } ExternalReference ExternalReference::new_space_allocation_limit_address() { return ExternalReference(Heap::NewSpaceAllocationLimitAddress()); } static double add_two_doubles(double x, double y) { return x + y; } static double sub_two_doubles(double x, double y) { return x - y; } static double mul_two_doubles(double x, double y) { return x * y; } static double div_two_doubles(double x, double y) { return x / y; } static double mod_two_doubles(double x, double y) { return fmod(x, y); } static int native_compare_doubles(double x, double y) { if (x == y) return 0; return x < y ? 1 : -1; } ExternalReference ExternalReference::double_fp_operation( Token::Value operation) { typedef double BinaryFPOperation(double x, double y); BinaryFPOperation* function = NULL; switch (operation) { case Token::ADD: function = &add_two_doubles; break; case Token::SUB: function = &sub_two_doubles; break; case Token::MUL: function = &mul_two_doubles; break; case Token::DIV: function = &div_two_doubles; break; case Token::MOD: function = &mod_two_doubles; break; default: UNREACHABLE(); } // Passing true as 2nd parameter indicates that they return an fp value. return ExternalReference(Redirect(FUNCTION_ADDR(function), true)); } ExternalReference ExternalReference::compare_doubles() { return ExternalReference(Redirect(FUNCTION_ADDR(native_compare_doubles), false)); } ExternalReferenceRedirector* ExternalReference::redirector_ = NULL; #ifdef ENABLE_DEBUGGER_SUPPORT ExternalReference ExternalReference::debug_break() { return ExternalReference(Redirect(FUNCTION_ADDR(Debug::Break))); } ExternalReference ExternalReference::debug_step_in_fp_address() { return ExternalReference(Debug::step_in_fp_addr()); } #endif } } // namespace v8::internal